Characteristics
Sickle cell disease (SCD) is a group of inherited red blood cell disorders in which an abnormal form of hemoglobin is produced (hemoglobin S, HbS). In normal circumstances the hemoglobin protein, which is found inside red blood cells, attaches to oxygen in the lungs and carries it to the different parts of the body. Healthy red blood cells are round and flexible, which allows them to move easily through blood vessels. Due to the abnormal HbS in SCD patients, red blood cells can take on a sickle shape as a reaction to certain types of stress, such as infections, dehydration, or cold weather. These abnormal sickle cells can stick together and block the blood flow, preventing oxygen from getting to vital organs and tissues throughout the body. This process can lead to serious complications including pain, infections, and organ damage. Furthermore, these sickle-shaped cells don’t live as long as normal red blood cells, causing a constant shortage of red blood cells.
Patient materials
Uitklappen
The cause of SCD is a defective gene, called a sickle cell gene. People with the disease are born with two sickle cell genes, one from each parent. Depending on the specific abnormalities in the inherited Hb genes, different SCD subtypes have been described. The most common (and most severe) of these subtypes is referred to as HbSS in which patients have inherited two defective HbS genes. When only one sickle cell gene is inherited, people are said to have sickle cell trait, or carriership. People with sickle cell trait are generally healthy, but they can pass the defective gene on to their children.
Symptoms
SCD patients will begin to experience symptoms from their disease very early in life, usually when they are just 5 to 6 months old. These early symptoms include a painful swelling of the hands and feet, fatigue or dizziness caused by anemia and a yellowish coloring of the skin (jaundice) or the whites of the eyes (icterus).
Throughout their life, patients with SCD experience periodic episodes of extreme pain. this pain is a result of a blocked blood flow through small blood vessels in the chest, abdomen, and joints and a lack of oxygen (ischemia) in the tissues behind the block. These pain episodes vary from patient to patient in intensity, frequency, and duration.
In addition to this, sickle cells may also damage the spleen, raising the risk of developing infections. In this respect, children with SCD require regular vaccinations and antibiotics to prevent potentially life-threatening infections, such as pneumonia.
Other sudden, and sometimes severe, complications that can occur in SCD patients include stroke, vision problems and acute chest syndrome. The latter occurs when sickled cells stick together and block the flow of oxygen in the lungs, leading to pneumonia-like symptoms, such as fever, pain, and a violent cough.
Diagnostic tests
SCD can be diagnosed through a hemoglobin electrophoresis, showing a hemoglobin S. In many countries, newborns are routinely tested for SCD. Of note, SCD can also be diagnosed in an unborn baby by sampling some of the amniotic fluid surrounding the baby in the womb.
Treatments
The treatment for SCD usually aims at avoiding pain episodes, relieving symptoms, and preventing complications. In practice, this is accomplished with a combination of blood transfusions and medication. This medication includes antimetabolites such as hydroxyurea, antibiotics to treat infections and painkillers. A stem cell transplantation stem cell transplantation can cure some people with SCD, but this treatment modality comes with a considerable risk.
In recent years, several new drugs are being developed, such as voxelotor and crizanlizumab, but reimbursement of these agents has been delayed or withdrawn due to a lack of proven cost-efficiency.
Relevant patient organisations
Get connected to different patient organisations that connect you to people with the same medical history. Support amongst peers helps the burden and stress of the daily challenges that come with disorders.
Find below some organisations we can recommend.
Be aware that these groups operate mainly in Dutch or French given their local nature, don’t hesitate to contact them nevertheless.
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